Thanks for explaining, although I did post this as a springboard to get replies.
As I have supported diskless UNIX systems for several years in the past (and will be again very shortly), I do understand about sharing a system image (which, incidental, on windows breaks a whole host of software unless you jump through hoops to redirect stuff away from the C: drive, which will be read-only, somewhere else - personal experience of pain here), and also identical hardware on the desktop. It's not a new technology except to Windows shops.
Citrix, VMWare and Microsoft are waaaaaaay behind the curve here compared to UNIX, both in diskless and remote display, and I have to feel that bending current windows to make it fit into a diskless/remote display model is the wrong way to go about it. Better would be to have made a 'new' windows with native thin client support and some compatibility with 'old' windows, than using a crowbar on the existing models. After all, MS did product switch before with NT. Maybe Longhorn should have been this, but they apparently could not get it to work without ex DEC system architects and IBM's assistance (WinNT history 101).
And I did talk about de-duplication, which is effectively what shared image is all about, and I did also talk about low power, diskless desktop display systems, but after a quick search, the only people I could find selling them was Wyse, who sell a diskless system running Windows CE for about the same price (once you factor peripherals in) as a basic PC. Many people in the past tried diskless PC's, and almost all of them are now NOT doing it (the earliest I remember was DEC Pathworks, which had diskless DOS systems with a network filesystem).
My closing comments about having been here before with other architectures still stand IMHO. I still think we have been here before, and I also still think that the current in-vogue implementations are flawed and designed to maximise revenue for suppliers rather than provide a good environment for customers.